1. Technical Field
The present invention relates to a semiconductor device, an ink cartridge, and an electronic device.
2. Related Art
There are conventional methods of managing ink consumption of ink cartridges in printers or the like that use ink for recording.
An example of such management methods is one which calculates ink consumption by using software to integrate the number of ink droplets ejected at the recording head and the amount of ink absorbed by maintenance.
However, this management method of using software to calculate ink consumption has problems such as the following.
There is weight variation in the ink droplets ejected in the head.
Although this weight variation of the ink droplets does not affect the image quality, it causes ink consumption amount errors which accumulate in the ink cartridge.
Consequently, the remaining amount of ink obtained by calculation and the actual remaining amount of ink differ, so that ink remains in the ink cartridge even though the remaining amount of ink is displayed as zero.
Users have noticed that exchanging a used ink cartridge with a new one even when ink remains results in a waste of the remaining ink.
In order to solve this problem, Japanese Unexamined Patent Application, First Publication No. 2002-283586 discloses a technique that uses a piezoelectric device to monitor the remaining amount of ink in an ink cartridge.
According to this method, the remaining amount of ink in the ink cartridge can be monitored using changes in the resonance frequency of a residual vibration signal generated by residual vibration of a vibration unit of the piezoelectric device.
However, in Japanese Unexamined Patent Application, First Publication No. 2002-283586, the sensor structure is complex and the accompanying system also becomes complex, increasing manufacturing costs.
Furthermore, when the ink cartridge is set inside a holder, an electrode terminal connected to the piezoelectric device contacts a contact terminal and becomes electrically connected to it.
However, in addition to the electrical connection between the electrode terminal of the piezoelectric device and the contact terminal in the holder, at least two or more electrical contact points are required between the ink cartridge and the main device, leading to concern over the reliability of the electrical connection.
Accordingly, the connections must be made secure to increase the reliability of the electrical contact points.
In the related art, systems wherein a detector for detecting ink information is independent from a storage unit for storing the ink information often store ink information detected via the main frame in the storage unit.
Consequently it is difficult to synthesize both types of information, and to perform simple and detailed information management such as ensuring that the ink cartridge cannot function unless it is set in the main device.